#1
|
|||
|
|||
Hum from magnetic pickup
Hi,
I have a Dean Markley magnetic soundhole pickup which I want to use while recording, to complement the external condenser microphone I use. The sound card is actually a mixer, a Behringer X-Air X18. With my setup I sit with my guitar facing the computer (with an external screen) and the microphones, but when doing this I get an annoying hum from the magnetic pickup channel, mostly at around 180 Hz and 450-500 Hz. Rotating the guitar 90 degrees, either vertically or horisontally, will make the hum almost disappear. I have tried to turn of the screen, but that doesn't help. I believe the Dean Markley is a single-coil, but I also have a Harley Benton SH30 pickup which I believe is a humbucker, and I do get a noise from that as well... although not as prominent. Any ideas what I can be? Most obvious is the electrical equipment of course, but I have tried to turn many of them off. When facing the computer with the guitar I also face north, can that affect? Distance to the computer doesn't seem to affect the hum sound, at least not in an obvious way. Are there any other magnetic sound hole pickups that are more resistant to this kind of problem? Thanks in advance! Per |
#2
|
|||
|
|||
Some humbuckers work better than others. I'd speculate that the amount of bucking you're getting is related to the quality of the design. I had a Fishman Rare Earth that was quiet, but it did sound like a magnetic pickup so I was never totally satisfied with the resultant sound.
Induced A.C. hum can be caused from a circuit running close by your area that is going to another part of your house, so not necessarily your computer setup. |
#3
|
||||
|
||||
Scratch the single coil. They are hopeless in many situations. Then, check the lighting. Some LEDs and CFLs will interfere. And make sure you have a high quality cable.
I assume you're plugged into a Hi-Z input with it set appropriately to that mode (if needed - never used one of those mixers). You might also try using a good DI box and go in to a "mic" level input with an XLR cable for better noise control. If the DI box has a ground lift, you can try that, too.
__________________
"I know in the morning that it's gonna be good, when I stick out my elbows and they don't bump wood." - Bill Kirchen |
#4
|
|||
|
|||
Quote:
I have tried to switch off the lights, doesn't help. And moving the guitar to the side, so that it still face the same direction (north) but not directly towards the computer does not help (but as I wrote earlier, rotating the guitar 90 degrees does take it away). The Dean Markley pickup has a long, built-in cable, and it seems pretty robust. I plug it into one the 2 Hi-Z inputs of the Behringer X18. In the end this hum will probably not be a problem in the recording as it hopefully won't be heard when I play. Also, the main recording of the guitar will come from the external condenser microphone, the magnetic pickup signal will only be used for adding some delay and other effects. It's annoying though, and I would like to invest in a better pickup. I think this is the pickup, but there's no text "Single coil" on mine (but it's pretty old): https://deanmarkley.com/collections/...guitar-pickups. I actually like the sound from it. /Per Last edited by Per Burström; 01-23-2022 at 10:33 AM. |
#5
|
|||
|
|||
Not sure on good solution for your setup, but the magnetic PU always seem to have some issues with noise and non acoustic sounds.
I have used the fishman rare earth with the mic and sounds ggreatin living room but howled for me on stage and had to use soundhole cover. I do like the mojotone NC-1 single coil mag PU that is engineered to minimize the typical hum, it really works well and sounds very nice. I just had it installed in my Iris this week after testing it for a month with the wire coming out of soundhole. |
#6
|
|||
|
|||
I've found a few comparisons between single coil and humbucker of the same brand on YouTube, for example the Fishman Neo-D, and I realize I prefer the single-coil sound. So I'll try some better than my Dean Markley.
I'll check out the NC-1. Any thoughts on the Shadow SH141? /Per |
#7
|
|||
|
|||
Quote:
A lot of work to experiment this way, but could be illuminating. |
#8
|
|||
|
|||
Have you tried not using the HI Z? The high impedance setting is for use with piezoelectric pickups that have an output impedance in the millions of ohms (megohm) range.
Magnetic pickups have one-thousandth (.001 ×) the output impedance of a piezo (kilohm). Is your Behringer running off battery or AC? It could be a floating ground issue. I would try grounding the case of everything the signal passes through. |
#9
|
|||
|
|||
Quote:
I tried to use one of the "normal" (non-HiZ) inputs, and it does indeed make it a little better, but the hum is still present. But as I wrote in my initial post the hum goes away if I rotate the guitar (and thereby the pickup) 90 degrees so the side and not the front of it face my equipment. Anyway, the hum will not be a problem in the recording anyway as it's drowned by the signal when I actually play the guitar. A bigger problem though is that the Dean Markley in a very obvious way change the acoustic sound from the guitar. But I guess all sound hole pickups that actually lock to the top of the guitar will do that?!? Anyone that has experience using the Shadow Nanonmag end of fretboard pickup? That must be the solution with the least effect on the guitars acoustic sound?!? https://www.customworldguitarparts.c...sh-nmg-pu.html Edit: Found a thread covering the Nanomag here: https://www.acousticguitarforum.com/...d.php?t=593692 Last edited by Per Burström; 01-24-2022 at 02:45 PM. |
#10
|
||||
|
||||
Quote:
If rotating the guitar changes the hum, you've got a source of EMI in the room (or walls!). It could be an old tube guitar amp, or just anything, but poor shielding and improper grounding can all contribute. Try different, shorter, perhaps better cabling (again, a good, short cable to a DI with a balanced run to the preamp), and watch where/how they are arranged. A decent humbucker is going to produce a lot less noise. (I replaced a single coil Fishman with the same looking humbucker version to fix a problem in a friend's guitar - he played sitting down in front of an old Acoustasonic amp.)
__________________
"I know in the morning that it's gonna be good, when I stick out my elbows and they don't bump wood." - Bill Kirchen |
#11
|
||||
|
||||
First thing I would do some quick subtractive diagnostics ,if you have not already done it
Set up the exact same way without the microphone, and see if you are still getting the hum.
__________________
Enjoy the Journey.... Kev... KevWind at Soundcloud KevWind at YouYube https://www.youtube.com/playlist?lis...EZxkPKyieOTgRD System : Studio system Avid Carbon interface , PT Ultimate 2023.12 -Mid 2020 iMac 27" 3.8GHz 8-core i7 10th Gen ,, Ventura 13.2.1 Mobile MBP M1 Pro , PT Ultimate 2023.12 Sonoma 14.4 Last edited by KevWind; 01-26-2022 at 12:06 PM. |
#12
|
|||
|
|||
Try grounding the strings. However, I can't think of any convenient way to do that (clip leads behind the saddle?).
__________________
jf45ir Free DIY Acoustic Guitar IR Generator .wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs IR Demo, read the description too: https://youtu.be/SELEE4yugjE My duo's website and my email... [email protected] Jon Fields |
#13
|
||||
|
||||
Some on-board systems were designed before wireless systems were in wide use, and are not properly shielded. If thats the case, not much you can do, except use a cord. Thats, if youre using wireless. Maybe Im off base.
__________________
Dave F ************* Martins Guilds Gibsons A few others 2020 macbook pro i5 8GB Scarlett 18i20 Reaper 7 |